1. Field of the Invention
The invention relates to azole derivatives having an anti-ulcerative activity and anti-ulcerative compositions containing at least one such azole derivative as an active ingredient.
2. Description of the Related Art
Agents which are effective for both inhibiting the secretion of gastric acid and protecting the gastrointestinal mucosa have been demanded as anti-ulcerative compositions.
As agents for inhibiting the secretion of gastric acid, there have been known histamine H.sub.2 -receptor antagonist typically represented by cimetidine. They are, however, ineffective for protecting the gastrointestinal mucosa. Because of their side effects upon the central nervous system, they are also less than satisfactory in their applicability to prevention or treatment of ulcers.
[H.sup.+ -K.sup.+ ] ATPase inhibitors typically represented by Omeprazole are strongly effective for inhibiting the secretion of gastric acid, but are known to induce achlorhydria. Another disadvantage of such inhibitors is that they are so unstable to acids that they are likely to be decomposed by gastric acid.
It is thus desired to develop anti-ulcerative agents which not only have a well-balanced effect of both inhibiting the secretion of gastric acid and protecting the gastrointestinal mucosae, but are also efficacious against various ulcers, low toxic and stable to the acid.
We have found that benzothiazole and benzimidazole derivatives have an anti-ulcerative activity (e.g. Japanese Patent Application Ser. No. 293689/88). As a result of further studies, we have now found that some azole derivatives are very efficacious against various, experimentally-induced ulcers, and possess both a strong effect of inhibiting the secretion of gastric acid and an enhanced effect on protecting the gastrointestinal mucosae.